It is known that certain fluoride-containing materials, which can be incorporated in resins used in dentistry as sealants, restoratives, and/or adhesives and also in devices such as denture reliners, orthodontic retainers, splint material, and finishing positioners, release fluoride ions at a rate sufficient to protect the adjacent tooth structure against caries. Specifically, Henry R. Rawls et al. have disclosed (U.S. Pat. Nos. 4,515,910 and 4,572,920) certain anion-exchange-site bearing monomers carrying fluoride ions which can be used to form interpolymers with other polymerizable monomers and which when used as dental materials slowly release fluoride ions at a rate sufficient to afford protection against caries.
In the aforementioned patents, the disclosures of which are incorporated herein by reference, the fluoride-containing materials are defined as polymerizable monomers containing an anion exchange site capable of carrying a fluoride ion, exemplified by certain alkylaminoalkyl acrylates or methacrylates. Specific examples of the fluoride-containing monomers taught by Rawls et al. are t-butylaminoethyl methacrylate hydrogen fluoride (t-BAEMA.HF), and N,N,N-trimethylaminoethyl methacrylate fluoride, which can be polymerized with alkyl acrylates and methacrylates, such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, capryl methacrylate, palmityl methacrylate, stearyl methacrylate, and the corresponding acrylate esters; bisphenol-A derivatives of acrylic and methacrylic acid, such as 2,2-bis[4-methacroyloxyphenyl]propane(Bis-MA), 2,2bis[4-(2-hydroxy-3-methacroyloxypropoxy)phenyl]propane(Bis-GMA) 2,2-bis[4-(2-methacroyloxy-ethoxy)phenyl]propane(Bis-EMA), and 2,2-bis[4-(3-methacroyloxy-propoxy)-phenyl]-propane(Bis-PMA); dimethacrylate derivatives of 1,2-cyclohexanedicarboxylic acid(c-HaDMA), and 4-cyclohexene-1,2-dicarboxylic acid(c-HeDMA); and dimethacrylate monomers containing urethane groups such as UEDMA and TUDMA, the structures of which are shown in Rawls U.S. Pat No. 4,572,920. The Rawls patents also describe the use for cross-linking in the interpolymers, of acrylic monomers such as ethyleneglycol dimethacrylate(EGDMA), trimethanolpropane trimethacrylate(TMPTMA), triethyleneglycol dimethacrylate(TEGDMA), polyethyleneglycol dimethacrylate(poly-EGDMA), and diethyleneglycol dimethacrylate(DEGDMA).
The interpolymers disclosed in the Rawls patents can be used either alone or together with filler materials such as silica to form dental materials for sealing or filling teeth while providing protection against caries.